Increasing photoperiod stimulates the initiation of spring migratory behaviour and physiology in a facultative migrant, the pine siskin
| Autor: | Heather E. Watts, Mali M. K. McGuire, Ashley R. Robart |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
bird migratory state Physiology photoperiod 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Zugunruhe 0302 clinical medicine Day length lcsh:Science 10. No inequality Siskin photoperiodism Facultative Multidisciplinary biology Obligate Spinus pinus facultative migration migratory restlessness biology.organism_classification testosterone lcsh:Q 030217 neurology & neurosurgery |
| Zdroj: | Royal Society Open Science, Vol 5, Iss 8 (2018) |
| ISSN: | 2054-5703 |
| Popis: | The transition to a migratory state involves coordinated changes in physiology and behaviour. In species with regular, predictable (obligate) migrations, increasing day length triggers the expression of a spring migratory state and androgens play an important role in stimulating its development. By contrast, we know little about the environmental cues and endocrine mechanisms that regulate migration in species with less predictable (facultative) migrations. Here, we tested whether photoperiod stimulates a migratory state in a facultative nomadic migrant, the pine siskin (Spinus pinus). We exposed wintering birds to either a naturally increasing or short-day photoperiod and measured physiological and behavioural changes indicative of a migratory state. We also examined changes in circulating hormones that may play a role in the migratory transition. Natural-day, but not short-day, birds displayed physiological preparations for migration, including increases in fat deposition, and showed increased levels of migratory restlessness. We found no evidence for a role of corticosterone in the migratory transition, but testosterone may be important. This study is the first experimental test of the role of photoperiod in regulating facultative migration and demonstrates that the predictive cue used by many obligate migrants to time spring migration is also important in a facultative migrant. |
| Databáze: | OpenAIRE |
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